[PATCH v5] mtd: rawnand: brcmnand: legacy exec_op implementation

David Regan dregan at broadcom.com
Fri May 23 10:02:30 PDT 2025


Hi Álvaro,

On Wed, May 21, 2025 at 1:03 AM Álvaro Fernández Rojas
<noltari at gmail.com> wrote:
>
> Commit 3c8260ce7663 ("mtd: rawnand: brcmnand: exec_op implementation")
> removed legacy interface functions, breaking < v5.0 controllers support.
> In order to fix older controllers we need to add an alternative exec_op
> implementation which doesn't rely on low level registers.
>
> Fixes: 3c8260ce7663 ("mtd: rawnand: brcmnand: exec_op implementation")
> Signed-off-by: Álvaro Fernández Rojas <noltari at gmail.com>
> Reviewed-by: David Regan <dregan at broadcom.com>
> ---
>  drivers/mtd/nand/raw/brcmnand/brcmnand.c | 222 ++++++++++++++++++++++-
>  1 file changed, 215 insertions(+), 7 deletions(-)
>
>  v5: add changes requested by Miquèl Raynal:
>   - Mention and explain legacy in native_cmd_conv.
>   - EOPNOTSUPP instead of EINVAL for instr->type else.
>   - Implement missing check_only functionality.
>
>  v4: add changes requested by Jonas Gorski:
>   - Add missing breaks in brcmnand_exec_instructions_legacy.
>   - Restore missing ret assignment in brcmnand_exec_op.
>
>  v3: add changes requested by Florian and other improvements:
>   - Add associative array for native command conversion.
>   - Add function pointer to brcmnand_controller for exec_instr
>     functionality.
>   - Fix CMD_BLOCK_ERASE address.
>   - Drop NAND_CMD_READOOB support.
>
>  v2: multiple improvements:
>   - Use proper native commands for checks.
>   - Fix NAND_CMD_PARAM/NAND_CMD_RNDOUT addr calculation.
>   - Remove host->last_addr usage.
>   - Remove sector_size_1k since it only applies to v5.0+ controllers.
>   - Remove brcmnand_wp since it doesn't exist for < v5.0 controllers.
>   - Use j instead of i for flash_cache loop.
>
> diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> index 299dd2bca5b4..5ed79ffa271c 100644
> --- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> +++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> @@ -65,6 +65,7 @@ module_param(wp_on, int, 0444);
>  #define CMD_PARAMETER_READ             0x0e
>  #define CMD_PARAMETER_CHANGE_COL       0x0f
>  #define CMD_LOW_LEVEL_OP               0x10
> +#define CMD_NOT_SUPPORTED              0xff
>
>  struct brcm_nand_dma_desc {
>         u32 next_desc;
> @@ -199,6 +200,30 @@ static const u16 flash_dma_regs_v4[] = {
>         [FLASH_DMA_CURRENT_DESC_EXT]    = 0x34,
>  };
>
> +/* Native command conversion for legacy controllers (< v5.0) */
> +static const u8 native_cmd_conv[] = {
> +       [NAND_CMD_READ0]        = CMD_NOT_SUPPORTED,
> +       [NAND_CMD_READ1]        = CMD_NOT_SUPPORTED,
> +       [NAND_CMD_RNDOUT]       = CMD_PARAMETER_CHANGE_COL,
> +       [NAND_CMD_PAGEPROG]     = CMD_NOT_SUPPORTED,
> +       [NAND_CMD_READOOB]      = CMD_NOT_SUPPORTED,
> +       [NAND_CMD_ERASE1]       = CMD_BLOCK_ERASE,
> +       [NAND_CMD_STATUS]       = CMD_NOT_SUPPORTED,
> +       [NAND_CMD_SEQIN]        = CMD_NOT_SUPPORTED,
> +       [NAND_CMD_RNDIN]        = CMD_NOT_SUPPORTED,
> +       [NAND_CMD_READID]       = CMD_DEVICE_ID_READ,
> +       [NAND_CMD_ERASE2]       = CMD_NULL,
> +       [NAND_CMD_PARAM]        = CMD_PARAMETER_READ,
> +       [NAND_CMD_GET_FEATURES] = CMD_NOT_SUPPORTED,
> +       [NAND_CMD_SET_FEATURES] = CMD_NOT_SUPPORTED,
> +       [NAND_CMD_RESET]        = CMD_NOT_SUPPORTED,
> +       [NAND_CMD_READSTART]    = CMD_NOT_SUPPORTED,
> +       [NAND_CMD_READCACHESEQ] = CMD_NOT_SUPPORTED,
> +       [NAND_CMD_READCACHEEND] = CMD_NOT_SUPPORTED,
> +       [NAND_CMD_RNDOUTSTART]  = CMD_NULL,
> +       [NAND_CMD_CACHEDPROG]   = CMD_NOT_SUPPORTED,
> +};
> +
>  /* Controller feature flags */
>  enum {
>         BRCMNAND_HAS_1K_SECTORS                 = BIT(0),
> @@ -237,6 +262,12 @@ struct brcmnand_controller {
>         /* List of NAND hosts (one for each chip-select) */
>         struct list_head host_list;
>
> +       /* Functions to be called from exec_op */
> +       int (*check_instr)(struct nand_chip *chip,
> +                          const struct nand_operation *op);
> +       int (*exec_instr)(struct nand_chip *chip,
> +                         const struct nand_operation *op);
> +
>         /* EDU info, per-transaction */
>         const u16               *edu_offsets;
>         void __iomem            *edu_base;
> @@ -2478,18 +2509,190 @@ static int brcmnand_op_is_reset(const struct nand_operation *op)
>         return 0;
>  }
>
> +static int brcmnand_check_instructions(struct nand_chip *chip,
> +                                      const struct nand_operation *op)
> +{
> +       return 0;
> +}
> +
> +static int brcmnand_exec_instructions(struct nand_chip *chip,
> +                                     const struct nand_operation *op)
> +{
> +       struct brcmnand_host *host = nand_get_controller_data(chip);
> +       unsigned int i;
> +       int ret = 0;
> +
> +       for (i = 0; i < op->ninstrs; i++) {
> +               ret = brcmnand_exec_instr(host, i, op);
> +               if (ret)
> +                       break;
> +       }
> +
> +       return ret;
> +}
> +
> +static int brcmnand_check_instructions_legacy(struct nand_chip *chip,
> +                                             const struct nand_operation *op)
> +{
> +       const struct nand_op_instr *instr;
> +       unsigned int i;
> +       u8 cmd;
> +
> +       for (i = 0; i < op->ninstrs; i++) {
> +               instr = &op->instrs[i];
> +
> +               switch (instr->type) {
> +               case NAND_OP_CMD_INSTR:
> +                       cmd = native_cmd_conv[instr->ctx.cmd.opcode];
> +                       if (cmd == CMD_NOT_SUPPORTED)
> +                               return -EOPNOTSUPP;
> +                       break;
> +               case NAND_OP_ADDR_INSTR:
> +               case NAND_OP_DATA_IN_INSTR:
> +               case NAND_OP_WAITRDY_INSTR:
> +                       break;
> +               default:
> +                       return -EOPNOTSUPP;
> +               }
> +       }
> +
> +       return 0;
> +}
> +
> +static int brcmnand_exec_instructions_legacy(struct nand_chip *chip,
> +                                            const struct nand_operation *op)
> +{
> +       struct mtd_info *mtd = nand_to_mtd(chip);
> +       struct brcmnand_host *host = nand_get_controller_data(chip);
> +       struct brcmnand_controller *ctrl = host->ctrl;
> +       const struct nand_op_instr *instr;
> +       unsigned int i, j;
> +       u8 cmd = CMD_NULL, last_cmd = CMD_NULL;
> +       int ret = 0;
> +       u64 last_addr;
> +
> +       for (i = 0; i < op->ninstrs; i++) {
> +               instr = &op->instrs[i];
> +
> +               if (instr->type == NAND_OP_CMD_INSTR) {
> +                       cmd = native_cmd_conv[instr->ctx.cmd.opcode];
> +                       if (cmd == CMD_NOT_SUPPORTED) {
> +                               dev_err(ctrl->dev, "unsupported cmd=%d\n",
> +                                       instr->ctx.cmd.opcode);
> +                               ret = -EOPNOTSUPP;
> +                               break;
> +                       }
> +               } else if (instr->type == NAND_OP_ADDR_INSTR) {
> +                       u64 addr = 0;
> +
> +                       if (cmd == CMD_NULL)
> +                               continue;
> +
> +                       if (instr->ctx.addr.naddrs > 8) {
> +                               dev_err(ctrl->dev, "unsupported naddrs=%u\n",
> +                                       instr->ctx.addr.naddrs);
> +                               ret = -EOPNOTSUPP;
> +                               break;
> +                       }
> +
> +                       for (j = 0; j < instr->ctx.addr.naddrs; j++)
> +                               addr |= (instr->ctx.addr.addrs[j]) << (j << 3);
> +
> +                       if (cmd == CMD_BLOCK_ERASE)
> +                               addr <<= chip->page_shift;
> +                       else if (cmd == CMD_PARAMETER_CHANGE_COL)
> +                               addr &= ~((u64)(FC_BYTES - 1));
> +
> +                       brcmnand_set_cmd_addr(mtd, addr);
> +                       brcmnand_send_cmd(host, cmd);
> +                       last_addr = addr;
> +                       last_cmd = cmd;
> +                       cmd = CMD_NULL;
> +                       brcmnand_waitfunc(chip);
> +
> +                       if (last_cmd == CMD_PARAMETER_READ ||
> +                           last_cmd == CMD_PARAMETER_CHANGE_COL) {
> +                               /* Copy flash cache word-wise */
> +                               u32 *flash_cache = (u32 *)ctrl->flash_cache;
> +
> +                               brcmnand_soc_data_bus_prepare(ctrl->soc, true);
> +
> +                               /*
> +                                * Must cache the FLASH_CACHE now, since changes in
> +                                * SECTOR_SIZE_1K may invalidate it
> +                                */
> +                               for (j = 0; j < FC_WORDS; j++)

Forgot to mention, not critical, but if you end up releasing a follow
on patch could you
please put braces around this part?

> +                                       /*
> +                                        * Flash cache is big endian for parameter pages, at
> +                                        * least on STB SoCs
> +                                        */
> +                                       flash_cache[j] = be32_to_cpu(brcmnand_read_fc(ctrl, j));
> +
> +                               brcmnand_soc_data_bus_unprepare(ctrl->soc, true);
> +                       }
> +               } else if (instr->type == NAND_OP_DATA_IN_INSTR) {
> +                       u8 *in = instr->ctx.data.buf.in;
> +
> +                       if (last_cmd == CMD_DEVICE_ID_READ) {
> +                               u32 val;
> +
> +                               if (instr->ctx.data.len > 8) {
> +                                       dev_err(ctrl->dev, "unsupported len=%u\n",
> +                                               instr->ctx.data.len);
> +                                       ret = -EOPNOTSUPP;
> +                                       break;
> +                               }
> +
> +                               for (j = 0; j < instr->ctx.data.len; j++) {
> +                                       if (j == 0)
> +                                               val = brcmnand_read_reg(ctrl, BRCMNAND_ID);
> +                                       else if (j == 4)
> +                                               val = brcmnand_read_reg(ctrl, BRCMNAND_ID_EXT);
> +
> +                                       in[j] = (val >> (24 - ((j % 4) << 3))) & 0xff;
> +                               }
> +                       } else if (last_cmd == CMD_PARAMETER_READ ||
> +                                  last_cmd == CMD_PARAMETER_CHANGE_COL) {
> +                               u64 addr;
> +                               u32 offs;
> +
> +                               for (j = 0; j < instr->ctx.data.len; j++) {
> +                                       addr = last_addr + j;
> +                                       offs = addr & (FC_BYTES - 1);
> +
> +                                       if (j > 0 && offs == 0)
> +                                               nand_change_read_column_op(chip, addr, NULL, 0,
> +                                                                          false);
> +
> +                                       in[j] = ctrl->flash_cache[offs];
> +                               }
> +                       }
> +               } else if (instr->type == NAND_OP_WAITRDY_INSTR) {
> +                       ret = bcmnand_ctrl_poll_status(host, NAND_CTRL_RDY, NAND_CTRL_RDY, 0);
> +                       if (ret)
> +                               break;
> +               } else {
> +                       dev_err(ctrl->dev, "unsupported instruction type: %d\n", instr->type);
> +                       ret = -EOPNOTSUPP;
> +                       break;
> +               }
> +       }
> +
> +       return ret;
> +}
> +
>  static int brcmnand_exec_op(struct nand_chip *chip,
>                             const struct nand_operation *op,
>                             bool check_only)
>  {
>         struct brcmnand_host *host = nand_get_controller_data(chip);
> +       struct brcmnand_controller *ctrl = host->ctrl;
>         struct mtd_info *mtd = nand_to_mtd(chip);
>         u8 *status;
> -       unsigned int i;
>         int ret = 0;
>
>         if (check_only)
> -               return 0;
> +               return ctrl->check_instr(chip, op);
>
>         if (brcmnand_op_is_status(op)) {
>                 status = op->instrs[1].ctx.data.buf.in;
> @@ -2513,11 +2716,7 @@ static int brcmnand_exec_op(struct nand_chip *chip,
>         if (op->deassert_wp)
>                 brcmnand_wp(mtd, 0);
>
> -       for (i = 0; i < op->ninstrs; i++) {
> -               ret = brcmnand_exec_instr(host, i, op);
> -               if (ret)
> -                       break;
> -       }
> +       ret = ctrl->exec_instr(chip, op);
>
>         if (op->deassert_wp)
>                 brcmnand_wp(mtd, 1);
> @@ -3130,6 +3329,15 @@ int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc)
>         if (ret)
>                 goto err;
>
> +       /* Only v5.0+ controllers have low level ops support */
> +       if (ctrl->nand_version >= 0x0500) {
> +               ctrl->check_instr = brcmnand_check_instructions;
> +               ctrl->exec_instr = brcmnand_exec_instructions;
> +       } else {
> +               ctrl->check_instr = brcmnand_check_instructions_legacy;
> +               ctrl->exec_instr = brcmnand_exec_instructions_legacy;
> +       }
> +
>         /*
>          * Most chips have this cache at a fixed offset within 'nand' block.
>          * Some must specify this region separately.
> --
> 2.39.5
>

Reviewed-by: David Regan <dregan at broadcom.com>

Thanks!

-Dave



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